Three climbers scaled Mount Everest over the weekend, and died on their descent. Two more are missing, too. All were among scores who happened to climb the mountain this weekend.

We're talking an estimated 150 climbers reached the summit during the weekend, most of them on Saturday.

An official said:

"There was a traffic jam on the mountain on Saturday. Climbers were still heading to the summit as late as 2:30 p.m. which is quite dangerous."

Because, regardless of how many people are doing it… it's still dangerous! Climbers are advised to not attempt to reach the summit after 11 a.m. for that very reason, and even the last camp at South Col is nicknamed the "death zone" because of the steep icy slope, treacherous conditions and low oxygen level!

"With the traffic jam, climbers had a longer wait for their chance to go up the trail and spent too much time at higher altitude. Many of them are believed to be carrying limited amount of oxygen not anticipating the extra time spent."

Exhaustion and altitude sickness were the probable cause of the three known deaths, for those very reasons.

The climbers were: 61-year-old German doctor Eberhard Schaaf, Canadian Shriya Shah, and South Korean mountaineer Song Won-bin. The missing climbers are: a Chinese national and his Nepalese Sherpa guide.